Pole guard



Dec.'30, 1952 D. c. HUBBARD 23,509

POLE GUARD.

Original Filed Aug. 8. 1949 A QJ 30 i f Q? i k JQM azaZiaavi ReissuedDec. 30, 1952 POLE GUARD David O. Hubbard, Centralia, Mo., assignor toA. B. Chance Company, Centralia, Mo., a cor-v poration of MissouriOriginal No. 2,534,170, dated December 1 2, 1950, I

Serial No. 109,145, August 8, 1949. Application I for reissue December7, 1951, Serial No. 260,380

Claims. H H Matter enclosed in heavy brackets I; 1 appears in theoriginal patent but forms-no part of, this; reissue specification;matter printed in' italics indicates the additionsmade by-reissue. r

The present invention relates to pole guards and is particularlyconcerned with insulating guards adapted to be applied to the poles ofhigh tension transmission lines when poles are bein manipulated oradjacent energized high voltage lines to install or remove a pole.

It has been found that creosoted poles are especially hazardous whenthey are manipulated of an improved protective device which is adaptedto prevent contact of the line pole with live conductors, either fromthe side or top, and which in addition provides a wide air-gap to insureagainst creepage currents or flash-over from the conductor to the pole.

Another object of the invention is the provision of an improved poleguard which provides an airgap between the pole and all live conductors,to prevent flash-over from the conductor to the pole, and in whichsurface leakage currents are minimized by providing long leakage pathsand a minimum contact area between any conductor engaging the guard andthe engagement of the guard with the pole itself. 7

Another object of the invention is the provision of an improved poleguard which is sturdy, capable of being collapsed into a small space,

easy to carry, and easy to assemble, capable of economical manufacture,and adapted to provide safety for linemen at the highest voltagesusually Fig. 2 is a top plan view of the pole guard of I Fig. 1;

Fig. 3 is a side elevational view;

Fig. 4 is a fragmentary sectional view, taken on the plane of the line4-4 of Fig. 3, looking in the direction of the arrows;

Fig. 5 is a fragmentary sectional, the plane of the line 5.5, 0f,Fig..3,1o0king in the direction of the arrows.

Referringto Figs. 1, to 3, l 0,:i r 1dicate s, a 11a; 1561's" which hasbeen provided with. a. pole guard em The twovertical frame assemblies [4and I5 I may be identical in construction, except for minor detailslater to be mentioned; Each of the frame assemblies may include angupperand a lower horizontal frame member llifll ofwood, or other suitableinsulating material;. The wood; employed is preferably igiln dried andofhigh' insulating. value, and covered with one or .more

coatings of insulatingvarnish.

The two frame members IE. I]

to the pole thatthere is, only a spot contactwith the sides ZO, 2! ofthe /-groove. Thisfminimizes creepage currents at this point. It alsogives double opposed bearing contact with the pole for each frame memberI6, I1.

Each frame member "5, I1 is provided with a 4 through bore 22 (Fig. 4)for passingascrew bolt.

23 and communicatingwith an enlarged countere bore 24 for passing andreceiving thehead 25 of the screw bolt. .Thus the head and shank o fthej screw bolt23 maybesorecessed and guardedi 'nside the frame membersIB and 11- that the metal.

screw bolts do not facilitate anyflash-over. The? bores and counterbores22, 24 are arranged adjacent the ends of the frame members I'B, l lsothat the screw bolts 23 may pass through bores 26 in the corner .poles,of which there are four,- indicated at 21-30. v

The poles 21-40 are also of similar insulating wood, similarly treated,and may be of; suitable size and diameter to withstand the forces ex.-.-

erted upon them. In -general,- they maybe of the same size as theinsulating, poles which are used? to. manipulate energized lineconductors. The length of the poles 21-30 is'preferably sufficient sothat the poles-extend from a point spaced from the upper endofth'eitransmissionline poledow'n wardly of the pole, past all liveconductors, when thetransm'ission line pole has 'its butt end resting aorm w a V-shaped groove l8 'th e .apex cf which is rounded at l9; andthe two si'des zll and ZI-are at such an angle, preferably acute, withrespect,

on the ground, before it is inserted into the hole in the earth... y

Thus there .isanotvdanger at any time: of thelinei pole coming incontact with live conductors because the live conductors will engage theinsulat ing poles 21-30 which are carried by the vertical frameassemblies I4 and I5.

The respective poles 2130. are clamped to the frame members l6, I! bywing-nuts-dk. When, the: two poles 21 and 28, for example; are clampedto the frame members l6 and [1, this provides a vertical frame assemblyfor engaging" one: side of the pole, as indicated by No. H":

The tension members I3 may consist of belts oi suitable insulatingfabric, such as a. webbing belt impregnated with insulatin andwaterproofvarni'si'rr and" these belts" .Iiif'are off suiiici'ent lengthto extend around" the assembly when it it is attached to a. pole 10;. Atone end the belt is provided. with. a buckle 32, through. which. the

free. end"; 33 may pass. so that. the,.b.e1t', can be.v tightenedaboutthe frame members. In order to, prevent.- the. belt. from slipping offthe, ends. of

The method of manipulating. and. using. the.

guardiis aatollowsz. Theguardis; applied, to a line. pole. while the;pole. is on the. ground; and. beforeit":israisedlthroughthealive.conductors... .Thetwo.

vertical. framev assemblies. 1.4? and. I5. are placed.

opposite each other at, the. endot' the: line. pole.

that. is. to. be; raised; between the conductors.

device; iszso positioned thatthe upper strap I 2.- is located beyondthe; upper. end. of; the. line.

pom. andthi's. strapv man bepulledsnuEly. around the. ends at the-poles.ofithe, two. frame assemblies.

and. secured. by.v means. of. the: buckle 32.. The hoolis thenpreventthe strap fromsliding off. the. ends at the. poles.

Then the second and Tower strap I3 may be pulledfirmlyaround the lowerendsof the frames and buckled. This. causes theunsupportedends of the.guardmemhers. or. poles. 2.1-3.0. tobow. in

wardly slightly at"v the. end. and outwardly at. the. middleandlappli'es grinning: pressure to the. line I pol'eat.the-V-shapednotches. I .8.

previously stated. they length of the guard. should be. such that itpreventsv thelive. conductors from engaging the. pole in every positionwhich. the pole may assume while it. is being. installed or liftedbetween the live conductors.

After the line pole hasbeen raised into position and? set; it is onlynecessary to release. the lower strap l3, spreading the two framemembers I'I 'atzthe-bottOm, which moves" the upper" ends of the guardpoles=2T -30 'towardeach otherandreleases the gripping: pressure-ofithe"upper strap I 2'.

hooks of? the frame assembly H may then her litted sufiicientlytodisengage the upper strap l2; from the. frame assembly M; therebyseparating the guardv intostwo: parts; the frame assembly l5; which;carries the straps; and the frame assembly' H... has been disengaged.from. the: s raps Thereaflter the, two; frames can readily be res.

.4 moved from the pole by lifting the upper strap, which. is. still"closed over the. top of the pole, the lower strap. l3 having beenopened. The wing nuts are provided to permit easy disassembly of theframes so they can be packed or stored in a small space.

The guard may also be used upon a pole that is to be removed. In suchcase the top strap i2 is adjustedand buckled to provide a loop ofsuitable size,.which is determined by trial or measurement. A preciseadjustment is not required.

The two frames are then raised, and the frame with. the-hooks 34 ispassed through the buckled upper loop or belt l2 as the lower ends ofthis frame. are. spread outward and the hooks are hooked over the belti2. After the upper strap Iris: engaged by" both frames, the guardisadjuste'd for proper height on the line pole; and then the lower endsare. brought in toward the pole and secured on it by means of the strap13. In some cases itmaybe necessary then to tightenor-adjust-the'upperstrap I 2.

The; present pole guards are adapted to prevent contact of the pole withlive conductors; The-spacing of the parts of the guard from the; linepole provides an air-gap which prevents a flash-over from the conductorto the pole. The contact between the-guard members 2?30 and theliveconductors is merely a point contact and a long leakage path is providedalong the guard membersto' the line po'leso that'surface leakagecurrents are minimized.

When a pole guard of the present construction is employed, fatalities,which might otherwise result from accidental contact of the pole withprimary-conductors, may be avoided. The dangeri's especially great withcreosoted poles; and the present; invention. fulfills an urgent need fora protective device for preventing energized C011. duotors fromcontacting line poles.

While I have illustrated a preferred embodimentofj my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not. wish to be limited to theprecise details, of.construction set forth, but desire" to avail myself of all changeswithin the scope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent-*ofthe United States, is:

1. In an insulated line pole assembly for safe installation betweenexisting energized line conductors, the combination of the line polewith a pair of insulating guard each guard unit including. a pair. ofWood pole engaging members ofisubstantially. rectangular. shape,provided with. a tapered groove having a rounded base for engaging polesof diiferent sizes, the pole engaging members of each unit beingparallel to each other and. the grooves being aligned with each other,an. insulating wooden pole carried by each of the outer corners. of. thepole engaging members of each unit, the insulating wooden poles being ofsuflicient length to extend from a point below the linev conductors to apoint beyond the top of the line pole, and a pair of insulating straps,eachstrap being located to extend about the end. portionsof the fourpoles of the two frame units to draw them together and. to cause thepole engaging members to clamp the line pole with a frictionalengagement and clamping force sufficient to insure the fixity of thepole guard on the line pole.

2;. In: an insulated line pole assembly for safeinstallation betweenexisting energized line con ductors, the combination of the line polewith a pair of insulating guard units, each guard unit including a pairof wood pole engaging members of substantially rectangular shape,provided with a tapered groove having a rounded base for engaging polesof different sizes, the pole engaging members of each unit beingparallel to each other and the grooves being aligned with each other, aninsulating wooden pole carried by each of the outer corners of the poleengaging members of each unit, the insulating wooden poles being ofsuflicient length to extend from a point below the line conductors to apoint beyond the top of the line pole, and a pair of insulating straps,each strap being located to extend about the end portions of the fourpoles of the two frame units to draw them together and to cause the poleengaging members to clamp the line pole with a frictional engagement andclamping force sufficient to insure the fixity of the pole guard on theline pole, the said insulating strap being fixedly secured to the poleend portions of one frame unit and the other pole end portion beingprovided with inwardly directed hooks for engaging the strap andpreventing it from passing off the ends of the pole end portions.

3. In an insulated line pole assembly for safe installation betweenexisting energized line conductors, the combination of a line pole witha pair of insulating guard units, each guard unit including a pair ofinsulating line pole-engaging members provided with tapered grooves forengaging line poles of difierent sizes, the line poleengaging members ofeach unit being spaced from each other, and the grooves being alignedwith each other, insulating poles carried by the line pole-engagingmembers of each unit, the insulating poles being of sufficient length toextend from a point below the line conductors to a point beyond the topof the line pole, and insulating tension members located to draw the endportions of the insulating poles of the two frame units toward the linepole and to cause the line poleengaging members to clamp the line polewith a frictional engagement and clamping force sufllcient to insure thefixity of the pole guard on the line pole.

4. In an insulated line pole assembly for safe installation betweenexisting energized line conductors, the combination of a line pole witha pair of insulating guard units, each guard unit including a pair ofinsulating line pole-engaging members provided with tapered grooves forengaging line poles of different sizes, the line poleengaging members ofeach unit being spaced from each other, and the grooves being alignedwith each other, insulating poles carried by the line pole-engagingmembers of each unit, the insulating poles being of sufllcient length toextend from a point below the line conductors to a point beyond the topof the line pole, and insulating tension members located to draw the endportions of the insulating poles of the two frame units toward the linepole and to cause the line poleengaging members to clamp the line polewith a frictional engagement and clamping force sufli cient to insurethe fixity of the pole guard on the line pole, the width and length ofsaid insulating line pole-engaging members being suflicient to space theinsulating poles from the line pole by a distance which prevents aflash-over from a line conductor engaging one or more of the insulatingpoles.

5. In an insulated line pole assembly for safe installation betweenexisting energized line conductors, the combination of a line pole witha pair of insulating guard units, each guard unit including a pair ofinsulating line pole-engaging members provided with tapered grooves forengaging line poles .of difierent sizes, the line polecngaging membersof each unit being spaced from each other, and the grooves being alignedwith each other, insulating poles carried by the line pole-engagingmembers of each unit, the insulating poles being of sufficient length toextend from a point below the line conductors to a point beyond the topof the line pole, and insulating tension members located to draw the endportions of the insulating poles of the two frame units toward the linepole and to cause the line pole-- engaging members to clamp the linepole with a frictional engagement and clamping force sumcient to insurethe fixity of the pole guard on "the line pole, said tension membersbeing located adiacent the lower end of the insulating poles andadjacent the upper end of the insulating poles, the upper tension memberforming an additional guard for protecting the upper end of the linepole from contact with energized conductors.

6. In an insulated line pole assembly for safe installation betweenexisting energized line conductors, the combination of a line pole witha pair of insulating guard units, each guard unit including a pair ofinsulating line pole-engaging members provided with tapered grooves forengaging line poles of different sizes, the line poleengaging members ofeach unit being spaced from each other, and the grooves being alignedwith each other, insulating poles carried by the line pole-engagingmembers of each unit, the insulating poles being of sufficient length toextend from a point below the line conductors to a point beyond the topof the line pole, and insulating tension members located to draw the endportions of the insulating poles of the two frame units toward the linepole and to cause the line pole-engaging members to clamp the line polewith a frictional engagement and clamping force sufitcient to insure thefirity of the pole guard on the line pole, the insulating poles beinground in cross-sectional shape to provide suficient strength sothat theinsulating poles have a point contact with any round line conductor,resulting in a minimum contact area and a minimum possibility of surfaceleakage of electrical current from the conductor to the line pole.

7. A transmission line pole guard comprising a pair of separableinsulating frames for mounting on a line pole, each frame including alower insulating pole-engaging member and an upper insulatingpole-engaging member for extending transversely to the line pole, andthe two poleengaging members of each frame being joined together by apair of guard poles of insulating material adapted to extendlongitudinally of the line pole and to keep line conductors fromengaging the line pole while the line pole is being moved adjacent theline conductors, and means for clamping said pole-engaging members on aline pole to secure the frames on the line pole with the insulatingpoles spaced from each other about th line pole to prevent any conductorwhich bridges two insulating poles from engaging the line pole.

8. A transmission line pole guard comprising a pair of separableinsulating frames for mounting on a line pole, each frame including alower insulating pole-engaging member and an upper insulatingpole-engaging member for extending 7? ttansuerselgl to the line. pole,and: the; two: pole-- engaging" members: of each. frame being joinedtogethen b g-'arpain off guardipoles of insulating material adaptedtoiemtendz longitudinally of the linepole and tazkeep vlineconductorsjromlengaging; the. line pole. while the. line pole is beingmovedada'aoentthe line conductors, and. means for clamping saidpole-engaging members on a line pole to secure the frames on the Zinepole with the insulating poles spaced from each other about. the lineole to prevent any cond r whichtbridges two" insulating poles fromengaging the: line; pole, said clamping means comprising tension-:meansacting on the: insulating poles to draw-them toward; the: line pole:

9;. A, transmission linev pole guard comprising a pairoffseparable;insulating framesfor mountaaline pole; each: frameingluding a lower insulating nale engagz'ng member and an. upperinsulating pole-engaging member for extending transperselg to the line.pole, and the two pole. engaging; members of each framebeing joinedtogether by a pair of guard poles of insulating material adapted toextend longitudinally of the line pole and; tolceepline conductors fromengaging the line'pole while the line pole isbeing moved adjacent. theline'conductors, and adjustable. securingmeans for drawing thepole-engaging 'membersinto; frictional engagement with line poles ofdifierent'sizes.

110. A. transmission Zinepolg guard comprising a pair of separableinsulating frames for-mountin onaaline pole; eachframeincluding a: lowerinsulating pole-engaging" member-- and an: upper insulatingpoleeengaging. member for e:z:te1ulin ,1,-v

transversely to. the line pole, and the two. poleengaging. members ofeach framebeing; joined.

together by a pair of guard poles of insulating material adapted toextend longitudinallgoj the line pole and to keep line conductors fromengag ing the line pole while the line pole is beingmoved adjacent theline conductors, and adjustable securing means for drawing thepole-engaging." members into frictional engagement with. line:

poles of difierent sizes, the said pole-engaging members being providedwith tapered grooves to; center line poles of diflerentlsizes; withrespect;

to .theinsulating guard poles.

DAVID C. HUBBARD.

REFERENCES CITED.

The following references are of record in the file of this patent or theoriginal patent:

UNITED. STATES PATENTS Number Name Date 1,200,976 Phelps Oct. 10; 1916:1,369,119 McKnight Feb. 22, 1921; 1,765,823 Burke June 24', 19301,979,688 Hamer .Nov. 6, 193.4.

OTHER REFERENCES Publication Electrical Record, February 1909, page 80.(Copy in Div. 65, Patent Ofiice);

